Expandable and contractible spindles are commonly used for winding and unwinding rolled products. Typical household spindles for dispensing toilet paper consists of three parts: two hollow elongated members and a spring. The two elongated members are sufficiently flexible such that one member can snap fit inside the other. The spring is located inside both members and applies a constant pressure to the elongated members, forcing them away from each other axially. In this manner, the spindle can be collapsed, placed in between a pair of arms or walls, and expanded into recesses of the arms or walls, thus securing the spindle in place. The outer diameter of the spindle fits in the center aperture of a roll of toilet paper, allowing the roll to unwind and dispense toilet paper.
These spindles are typically designed for standard rolls of toilet paper that have a cardboard paper core approximately 1½ inches (3.8 cm) in diameter. The toilet paper is wound over the cardboard paper core, generally until the outer diameter reaches approximately 4½ in diameter (11.4 cm).
In order to prevent pilferage of toilet paper in commercial settings, either by the bathroom user or maintenance staff, manufacturers of commercial rolls of toilet paper have produced “solid-core,” “coreless,” and “reduced-core” toilet paper rolls. As used herein, “solid-core” means a roll of product that has substantially no center aperture. As used herein, “coreless” means a roll of product having no separate core material (e.g., cardboard core for toilet paper). “Coreless” also generally implies that the center aperture of the roll of product is less than that of a similar size roll having a core, although this may not always be the case. As used herein, “reduced-core” means a roll of product that has a core diameter substantially smaller than a standard or common core diameter (e.g., 1½ inches for residential-use toilet paper rolls). Solid-core, coreless, and reduced core toilet paper rolls discourage theft of the rolls since the rolls cannot be used with most residential toilet paper roll dispensers and spindles.
The typical spindle design described above (i.e., two elongated members that snap fit together with a spring inside) is not well suited for rolls having smaller center apertures since a snap fit connection looses effectiveness as dimensions are reduced. The snap fit connection becomes more fragile as the diameter of the elongated member is reduced. The snap fit connection also becomes more fragile as the thickness of the wall of the elongated member is increased in order to have enough strength to hold the paper product during use. This thicker wall is less flexible and can crack when the two parts are snapped together. Numerous spindle designs for coreless paper product rolls are known. U.S. Pat. No. 5,467,935 to Moody, for example, describes a spindle for dispensing coreless rolls of toilet paper. The spindle incorporates a stop mechanism to prevent the roll from making complete revolutions, thus limiting the amount of toilet paper that can be dispensed in order to reduce usage and save money. Other spindle designs are taught in U.S. Pat. Nos. 1,391,326, 1,778,856, 2,209,471, 2,289,453, 2,289,519, 2,331,743, 2,621,867, 2,762,575, 3,770,221, 4,212,434, 4,447,015, 6,422,505, D0340822, International Patent Application Publication No. WO 2009/027873, and Great Britain Patent No. 731449.
These and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
All known prior art has failed to provide an expandable/contractible spindle design that is well suited for rolls having reduced diameter center apertures. The spindle disclosed in Moody, for example, is overly complex and the stop feature is undesirable for most users. It has yet to be appreciated that an expandable/contractible spindle can be provided that does not rely on snap connections.
Thus, there is still a need for an improved expandable/contractible spindle that can be used with rolls of paper products having reduced diameter center apertures.